Filtering pipe for well



United States Patent lnventor Wilhelm Degen Zeppelinallee 89, Frankfurt, Germany Appl. No. 767,672 Filed Oct. 15, 1968 Patented Dec. 1, 1970 Priority Oct. 17, 1967 Austria No. A9364/67 FILTERING PIPE FOR WELL 4 Claims, 4 Drawing Figs.

US. Cl 166/228; 210/496 Int. Cl E031) 3/18; E2 1 b 43/00 [50] Field ofSearch 166/228; 210/496, 510

[56] References Cited UNITED STATES PATENTS 260,803 7/1882 Tichenor 166/235 907,328 12/1908 Freeman 210/496 3,034,655 5/1962 York 210/496 Primary Examiner-James A. Leppink Attorney- Kurt Kelman ABSTRACT: The pipe sections of a well filtering pipe each comprises a water permeable tubular wall of a bonded granular material, and a plurality of elongated supports embedded within the wall and extending uniformly about the axis.

Patented Dec. 1, 1970 3,543,854

Fig. 4

Mum/0r: LJILHELH 356m MM 14w A6 GMT- FILTERING PIPE FOR WELL Background and Summary of the Invention The present invention relates to filtering pipes or casings for artesian wells. Such casings may consist of such granular materials as gravel bonded together by such adhesives as synthetic resin or vulcanized rubber, and may be reinforced with suitable support elements to prevent bending.

Artesian wells are usually constructed by first sinking a shaft of sufficient diameter, than placing a slitted filter pipe into the shaft, and finally pouring gravel between the shaft wall and the pipe. Although relatively. simple, building of deep wells of this type is relatively difficult and requires expert labor. For this reason, a variety of prefabricated filtering pipes for wells have been proposed. It is an object of this invention to provide an improved filter pipe section for well casings.

This object is accomplished by embedding a plurality of elongated support elements in the tubular wall of the pipe, with the support elements extending parallel to the axis of the pipe and being uniformly distributed within the wall. This provides minimal dimensioning and maximum filtering effect.

Brief Description of Drawing The above and other objects, advantages and features of the present invention will be better understood by reference to the following detailed description of certain preferred embodiments, taken in conjunction with the accompanying drawing wherein FIG, 1 is a perspective side view of an artesian well filter pipe; and

FIGS. 2 to 4 are cross sections of the wall of the pipe showing different embodiments of support elements.

Detailed Description Referring to the drawing and first to FIG. 1, the filter pipe is shown to comprise filter pipe section 1 having end flanges 2 to enable the pipe section 1 to be attached to like pipe sections fonning the filter pipe of an artesian well. In view of the sturdy construction, each filter pipe section may be relatively long, requiring only a few flange connections between adjacent sections even in a relatively deep well. As appears particularly from the cutout portion of the pipe section wall in FIG. 1, the tubular wall 4 of the filter pipe sections consists of a water permeable, bonded mass of gravel wherein the elongated support elements 3 are embedded, i.e. the wall is not constituted by support elements carrying filter plates therebetween as has been conventional.

In other words, each filter pipe section is a self-supporting filter pipe consisting of a suitable granular material, such as gravel, which is bonded by a suitable adhesive substance, such as a synthetic resin or vulcanizable rubber, to form a water permeable wall.

In the embodiment of FIG. 1, the elongated support elements 4 are of T-shaped cross section, being so embedded in the pipe wall that the cross bar 9 of each T-section is flush with the outer surface 5 of the wall while the other bar of the T-section points inwardly towards the axis of the pipe section, see FIG. 4. Extending the other T-section bar of the support elements substantially to the center line 6 of the pipe section wall is particularly advantageous because the flow section tapers a the sup e minimum towards the inner surface 11 of the wall and the pipe axis (see broken line conus in FIG. 4). This causes the radially extending section 11 behind the support elements to have a maximum extension.

FIG. 2 shows a support element 7 of substantially square cross section, with the flow lines again indicated in broken lines. within FIG. 3 shows another advantageous form of a support element 8 of elongated, rectangular cross section. These elements are radially arranged withing the pipe section wall, the center line 6 of the wall substantially bisecting the length of rt elements. In a mbodiments, the support elements are completely, or

at least largely, embedded in the pipe section wall, which produces advantageous dimensionally conditions for the support elements and for the wall thickness. The filtering wall and its support constitutes a unitary tubular body, the built-in sup port elements serving to prevent bending of the filtering mass in any direction. Outward bending is prevented by the soil surrounding the pipe section. The support elements may be relatively small since, being parallel to the filter pipe line, they need to support only the tensile load and are not subjected to a bending element. Thus, the filtering mass of the wall and the support elements complement each other in supporting the loads to which the pipe sections are subjected, the relatively small section of the support elements correspondingly increasing the cross section of the water permeable filter wall.

A series of experiments in artesian wells have shown, for instance, that filter pipes having a diameter of 30 cm. could be reduced in wall thickness from l0 to 3 cm., with support elements embedded in the wall of the pipe according to the present invention. This not only reduces the material cost of the pipe sections, but also minimizes transportation and construction costs because of the reduced weight of the pipe sections.

Mounting the support elements in the outer portion of the pipe wall, i.e. between the outer wall surface and the center line of the wall, is particularly advantageous. On the one hand, this produces a relatively large cross section of the wall radially behind the embedded support elements and, on the other hand, it increases the effective flow section of the filtering portion of the wall because the entire inner-half of the wall behind the center line is thus kept free for filtering purposes.

I claim:

l. A pipe section for a filtering pipe for a well, comprising:

1. a water permeable tubular wall having an axis and comprised of gravel bonded by a synthetic resin or vulcanizable rubber adhesive; and

2. a plurality of elongated support elements extending parallel to the axis and embedded within a radially outward portion of the wall, the support elements being uniformly distributed within the wall.

2. The pipe section of claim 1, wherein the support elements are of T-shaped cross section.

3. The pipe section of dam 2 wherein the cross bar of the T-shaped support element extends along the circumference of the wall and the elongated bar of the T-shaped support ele- 

